Dewats, an answer to sewage treatment: Experts

NAGPUR: With cities all over the world growing at a very fast pace, providing adequate sanitation to the people especially through sewerage and waster water management has emerged as a big challenge for the administration.

Customized De-centralized Waste Treatment System (Dewats), that uses different technologies for waste water treatment depending on the site and the local problems associated with sanitation, has emerged as a solution to the problem of urbanization.

Experts from various governmental as well as non governmental agencies at the three day international conference on decentralized wastewater management in Asia which began on Tuesday voiced that site specific Dewats is a viable sanitation option for Asian countries.

Susmita Sinha of the Consortium for Dewats Dissemination Society (CDD) from Bangalore said that the CDD partnerships had yielded good results in Asian countries like India, Pakistan, Bhutan, Nepal, Bangladesh and Sri-Lanka. "Dewats have been used as modular treatment systems with customized and incremental designs in collaboration with the City Sanitation Plan (CSP) in many cities in these countries," she said.

Stefan Reuter, director of Bremen Overseas Research and Development Association (Borda), Germany felt that combining the centralized water sewerage system with Dewats was a smart way of handling the problem. But unfortunately lack of coordination between the agencies handling this hampers the development rather than hastening it. Meanwhile, use of a combination of anaerobic technology with an aerated filtering system which can drain the treated water to the right place has shown good results in Indian cities like Kolhapur, Pune, Nagpur, Chennai and Bangalore.

"These biogas plants can work well in both in domestic and food processing sector as no chemical are involved here," he said.

The union ministry of urban development has decided to collaborate with the Deusche Gesellschat fur Internationle Zusammenarbeit (GIZ) from 2011 to 2018. Regina Dube, senior adviser of the programme on 'Support to the National Urban Sanitation Policy' stressed that GIZ will only provide technological support to cities. Dube said that cities just need to priortise their implementation strategies. In India six cities are in process of getting their CSPs approved by the respective state departments of ministry of urban development.

While most countries in Asia are already using Dewats, Afghanistan is still in the process of evolving a national policy on environment and sanitation. Hussain Etemadi, the director of water supply of ministry of urban development pointed out that the country had recently held a meeting of all the stakeholders involved in the process. At present, big cities are using decentralized systems like septic tanks. But since groundwater is one of the major sources of drinking water, groundwater pollution is emerging as a big challenge.

Ryan Yuen from the International Water Association sees the association as the link which joins all the countries seeking information or technical support on Dewats. "We reach out to different government and influence them positively in deciding their policies," he said.